Refrigerated point-of-use holding cabinet

• US 8,607,587 B2
• Filed: 05/19/2010
• Issued: 12/17/2013
• Est. Priority Date: 05/19/2010
• Status: Active Grant

• Current Assignee: Marmon Foodservice Technologies Incorporated (Berkshire Hathaway Incorporated)
• Original Assignee: Prince Castle LLC (Berkshire Hathaway Incorporated)
• Inventors: Veltrop, Loren
• Primary Examiner(s): ROHRHOFF, DANIEL J
• Application Number:
  US12/782,843
• Publication Number:
  US 20110283714A1
• Time in Patent Office: 1,308 Days
• Field of Search: 622/52, 622/53, 623/82, 624/31, 624/41, 624/43, 624/47
• US Class Current: 62/443
• CPC Class Codes: A47F 3/06 with movable or removable shelves or receptacles A47F3/0486 takes precedence; display racks with movable parts A47F5/0081
• CPC Class Codes: F25B 21/02 using Peltier effect; using Nernst-Ettinghausen effect
• CPC Class Codes: F25D 19/006 Thermal coupling structure or interface
• CPC Class Codes: F25D 23/003 for cooling refrigerating machinery
• CPC Class Codes: F25D 25/028 Cooled supporting means
• CPC Class Codes: F25D 2700/16 Sensors measuring the temperature of products

Abstract

A refrigerated point-of-use food holding cabinet keeps food products cold in compartments having cross sections that are substantially U-shaped. Food products are kept refrigerated using heat-absorbing, heat-exchangers thermally coupled to the U-shaped compartment. Refrigeration is provided by either a conventional reversed-Brayton cycle, one or more Peltier devices or a chilled, re-circulating liquid that does not change phase as it circulates but which is chilled by another refrigeration system, such as a conventional refrigeration system. An optional cover helps prevent food flavor transfers between compartments. Semiconductor temperature sensors and a computer effectuate temperature control.

Claims

1. A food holding cabinet comprising:

a first, substantially U-shaped thermally-conductive, tray receiving member having a substantially planar bottom, generally planar first and second side opposing walls that extend upwardly from the substantially planar bottom, and first and second opposing open ends, the substantially planar bottom and generally planar side walls having inside surfaces and outside surfaces, the substantially U-shaped thermally-conductive tray receiving member defining a substantially U-shaped cavity in which food or a food holding tray can be placed through either of the first and second opposing open ends, such that food or a food holding tray placed in the first tray receiving member will be in direct contact with the substantially planar bottom of the tray receiving member, the cavity having ends, at least one of which is open;

a liquid phase/vapor phase refrigeration system comprising a pressurized gaseous working fluid, a compressor, which compresses the working fluid, a condenser coupled to the compressor, and

a first substantially U-shaped evaporator coil coupled to the condenser, the first evaporator coil being attached directly to the outside surfaces of the substantially planar bottom and both generally planar sidewalls of the first substantially U-shaped thermally-conductive tray receiving member, the first evaporator coil being configured to conduct heat energy away from the substantially parallelepiped-shaped thermally-conductive, tray receiving member and thereby conduct heat energy away from a substantially planar bottom surface of a food holding tray placed on the substantially planar bottom of the first tray receiving member and conduct said heat energy into the working fluid flowing through the first evaporator coil.

2. The food holding cabinet of claim 1, further comprising a second, substantially U-shaped thermally-conductive, tray receiving member having a substantially planar bottom, generally planar first and second opposing side walls that extend upwardly from the substantially planar bottom, and, first and second opposing and open ends, the substantially planar bottom and generally planar side walls having inside surfaces and outside surfaces, the second substantially parallelepiped-shaped thermally-conductive tray receiving member defining a second, substantially U-shaped cavity in which food or a food holding tray can be placed through either of the first and second opposing open ends, such that food or a food holding tray placed in the second tray receiving member will be in direct contact with the substantially planar bottom of the tray receiving member, the cavity having ends, at least one of which is open;

and

a second, substantially U-shaped evaporator coil attached directly to the outside surfaces of the substantially planar bottom and both generally planar sidewalls of the second substantially U-shaped thermally-conductive tray receiving member, the second evaporator coil being configured to conduct heat energy away from the second substantially U-shaped thermally-conductive, tray receiving member and thereby conduct heat energy away from a substantially planar bottom surface of a food holding tray placed on the substantially planar bottom of the second tray receiving member; and

wherein the second, evaporator coil is connected in series to the first evaporator coil.

3. The food holding cabinet according to claim 2, wherein the first and second evaporator coils are substantially boustrophedonic.

4. The food holding cabinet according to claim 3, wherein the evaporator coils are generally U-shaped and conform to the shape of the tray receiving members.

5. The food holding cabinet according to claim 2, further comprising an electrically-resistive wire coupled to the first, tray receiving member and configured to provide heat energy to the first tray receiving member.

6. The food holding cabinet according to claim 1, further comprising a first transistor comprising a P-N junction, the transistor being mechanically and thermally coupled to the first, tray receiving member and which is configured to effectuate control of the temperature of the first tray-receiving member by a calculation of the P-N junction'"'"'s temperature from a measurement of a voltage across the P-N junction.

7. The food holding cabinet according to claim 6, further comprising an electrically-resistive wire coupled to an outside surface of at least one of the generally planar side walls and the substantially planar bottom of the second tray receiving member, and which is configured to add heat to the second tray receiving member.

8. The food holding cabinet of claim 7, further comprised of a second transistor, comprising a P-N junction, the transistor being mechanically and thermally coupled to the second tray-receiving member and configured to effectuate control of the temperature of the second tray-receiving member, independently of the temperature of the first tray-receiving member.

9. A food holding cabinet comprising:

at least one tier;

first and second tray-receiving members within the at least one tier of the cabinet, each of the tray-receiving member being substantially parallelepiped-shaped, having a generally U-shaped cross-section having a substantially horizontal and substantially planar bottom and generally planar and opposing side walls extending substantially vertically from the substantially planar horizontal bottom, and first and second opposing and open ends, the ends being sized, shaped and arranged to allow a food storage tray to pass through them, the tray receiving members being configured such that food or a food holding tray placed in a tray receiving member will be in direct contact with the bottom of the tray receiving member; and

a first, substantially U-shaped evaporator coil attached directly to outside surfaces of the substantially planar bottom and both substantially planar sidewalls of the first substantially parallelepiped-shaped thermally-conductive tray receiving member;

a second substantially U-shaped evaporator coil attached directly to outside surfaces of the substantially planar bottom and both substantially planar sidewalls of the second substantially parallelepiped-shaped thermally-conductive tray receiving member, the second evaporator coil being connected in series with the first evaporator coil;

a single liquid phase/vapor phase refrigeration system comprising a pressurized gaseous working fluid and a refrigeration compressor, which is coupled to the series-connected evaporator coils and configured to provide pressurized gaseous refrigeration working fluid to both of the series-connected evaporator coils;

whereby heat energy from a food item or food storage tray placed onto a substantially planar bottom of a substantially parallelepiped-shaped thermally-conductive tray receiving member is conducted into working fluid passing through the corresponding evaporator coil.

10. The food holding cabinet of claim 9, further comprised of:

first and second cover members in corresponding ones of the first and second tray receiving members, each cover member having a horizontal web section that extends generally horizontally between opposing generally planar side walls of the first and second tray-receiving members respectively, the horizontal web section being sized, shaped and arranged to enclose the first and second tray-receiving members in which food holding trays are located;

whereby a food holding tray placed in a tray-receiving member will be covered by said cover members.

11. The food holding cabinet according to claim 10, wherein the first and second tray-receiving members have generally planar side walls that have shoulders configured to support the cover members.

12. The food holding cabinet of claim 9, further comprising an electrically-resistive wire coupled to at least one of the first and second tray-receiving members, the electrically-resistive wire being configured to provide heat to the at least one of the first and second tray-receiving members.

13. The food holding cabinet according to claim 9, further comprised of a compartment-separating wall between the first and second tray-receiving members.

14. The food holding cabinet of claim 13, wherein the compartment separating wall is thermally insulated.

15. The food holding cabinet of claim 9, further comprised of a first transistor that is mechanically coupled to at least one thermally-conductive tray-receiving member and configured to effectuate temperature control of the at least one tray-receiving member.

16. The food holding cabinet of claim 15, further comprised of a controller, configured to effectuate control of the compressor responsive to the transistor.

17. A food holding cabinet configured to absorb heat from food held in thermally-conductive food holding trays inside the food holding cabinet, the food holding trays being configured to have a bottom surface, generally planar side walls and end walls, both side walls and end walls extending upwardly from the bottom surface to an upper rim and providing an upwardly opening interior for holding food therein, the food holding cabinet, comprised of:

a cabinet;

a plurality of substantially parallelepiped-shaped thermally-conductive, tray receiving members in the cabinet, each of the tray-receiving members having a substantially horizontal and substantially planar bottom, substantially vertical and generally planar opposing side walls extending substantially vertically from the substantially horizontal and substantially planar bottom, and first and second opposing and open ends, which are sized, shaped and arranged to allow said food holding trays to pass through them, the substantially parallelepiped-shaped tray-receiving members being configured such that side walls of food holding trays placed within a tray-receiving member will be adjacent the side walls of the tray-receiving members in which food holding trays are placed, the tray receiving members being additionally configured such that food or a food holding tray placed in a tray receiving member will be in direct contact with the substantially horizontal and substantially planar bottom of the substantially parallelepiped-shaped tray receiving member;

a plurality of evaporator coils, at least one evaporator coil being attached directly to outside surfaces of the bottom and both sidewalls of each of the plurality of tray receiving members, the evaporator coils being connected in series with each other, the series-connected evaporator coils being connected to a single liquid phase/vapor phase refrigeration compressor configured to provide pressurized, gaseous refrigeration working fluid to the series-connected evaporator coils;

whereby heat energy in food or a food holding tray placed on the bottom of the substantially parallelepiped-shaped tray-receiving member be conducted into the working fluid.

18. The refrigerated food holding cabinet of claim 17, wherein the tray-receiving members side walls are configured to isolate food holding trays in adjacent tray-receiving members from each other, in the cabinet.

19. The food holding cabinet of claim 17, wherein the generally planar side walls of the tray-receiving members have horizontal shoulders, located upwardly from the horizontal bottom.

20. The food holding cabinet of claim 19, wherein the food holding cabinet further comprises a removable food holding tray cover located in the cabinet and resting on the horizontal shoulders.

21. The food holding cabinet of claim 17, wherein the food holding cabinet is comprised of first and second tiers, the first tier being stacked above the second tier, both tiers being comprised of first and second substantially parallelepiped-shaped tray-receiving members, the first tier being thermally separated from the second tier, the first and second tray-receiving members in each tier being thermally separated from each other.

22. The food holding cabinet of claim 21, wherein the first and second tiers are defined by horizontal surfaces above and below each tier.

23. The food holding cabinet of claim 22, wherein tray-receiving members in each tier are attached to a horizontal surface above each tier.

24. The food holding cabinet of claim 22, wherein tray-receiving members in a tier are separated from each other by a vertical wall.

25. The food holding cabinet according to claim 17, wherein the generally planar side walls of the tray-receiving members have upper and lower regions defined by horizontal shoulders in said generally planar side walls.

26. The food holding cabinet according to claim 25, further comprising a thermally-conductive food holding tray within a tray-receiving member, the food holding tray having a rim projecting laterally from side walls of the tray and which rests on the horizontal shoulders in said generally planar side walls of the tray-receiving member.

27. The food holding cabinet of claim 17 further comprised of a semiconductor temperature sensor operatively coupled to at least one thermally-conductive tray-receiving member.

28. The food holding cabinet of claim 27 further comprised of a controller, operatively coupled to the semiconductor temperature sensor and effectuating control of the heat-absorbing refrigeration element.